[ttFont] Add getGlyphIDMany(); use in otLayout

Fixes https://github.com/fonttools/fonttools/issues/1536
Superced https://github.com/fonttools/fonttools/pull/1654

Part of https://github.com/fonttools/fonttools/pull/2398

Lib/fontTools/misc/testTools.py

@@ -57,6 +57,9 @@ class FakeFont:
     def getGlyphID(self, name):
         return self.reverseGlyphOrderDict_[name]
 
+    def getGlyphIDMany(self, lst):
+        return [self.getGlyphID(gid) for gid in lst]
+
     def getGlyphName(self, glyphID):
         if glyphID < len(self.glyphOrder_):
             return self.glyphOrder_[glyphID]

Lib/fontTools/ttLib/tables/otConverters.py

@@ -347,18 +347,11 @@ class GlyphID(SimpleValue):
 	staticSize = 2
 	typecode = "H"
 	def readArray(self, reader, font, tableDict, count):
-		gids = reader.readArray(self.typecode, self.staticSize, count)
-		return font.getGlyphNameMany(gids)
+		return font.getGlyphNameMany(reader.readArray(self.typecode, self.staticSize, count))
 	def read(self, reader, font, tableDict):
 		return font.getGlyphName(reader.readValue(self.typecode, self.staticSize))
 	def writeArray(self, writer, font, tableDict, values):
-		glyphMap = font.getReverseGlyphMap()
-		try:
-			values = [glyphMap[glyphname] for glyphname in values]
-		except KeyError:
-			# Slower, but will not throw a KeyError on an out-of-range glyph name.
-			values = [font.getGlyphID(glyphname) for glyphname in values]
-		writer.writeArray(self.typecode, values)
+		writer.writeArray(self.typecode, font.getGlyphIDMany(values))
 	def write(self, writer, font, tableDict, value, repeatIndex=None):
 		writer.writeValue(self.typecode, font.getGlyphID(value))
 

Lib/fontTools/ttLib/tables/otTables.py

@@ -549,10 +549,9 @@ class Coverage(FormatSwitchingBaseTable):
 			glyphs = self.glyphs = []
 		format = 1
 		rawTable = {"GlyphArray": glyphs}
-		getGlyphID = font.getGlyphID
 		if glyphs:
 			# find out whether Format 2 is more compact or not
-			glyphIDs = [getGlyphID(glyphName) for glyphName in glyphs ]
+			glyphIDs = font.getGlyphIDMany(glyphs)
 			brokenOrder = sorted(glyphIDs) != glyphIDs
 
 			last = glyphIDs[0]
@@ -751,7 +750,7 @@ class SingleSubst(FormatSwitchingBaseTable):
 		input = _getGlyphsFromCoverageTable(rawTable["Coverage"])
 		if self.Format == 1:
 			delta = rawTable["DeltaGlyphID"]
-			inputGIDS =  [ font.getGlyphID(name) for name in input ]
+			inputGIDS = font.getGlyphIDMany(input)
 			outGIDS = [ (glyphID + delta) % 65536 for glyphID in inputGIDS ]
 			outNames = font.getGlyphNameMany(outGIDS)
 			for inp, out in zip(input, outNames):

Lib/fontTools/ttLib/ttFont.py

@@ -533,6 +533,7 @@ class TTFont(object):
 			return self.getGlyphOrder()[glyphID]
 		except IndexError:
 			return "glyph%.5d" % glyphID
+
 	def getGlyphNameMany(self, lst):
 		glyphOrder = self.getGlyphOrder();
 		cnt = len(glyphOrder)
@@ -540,14 +541,15 @@ class TTFont(object):
 			for gid in lst]
 
 	def getGlyphID(self, glyphName):
-		if not hasattr(self, "_reverseGlyphOrderDict"):
-			self._buildReverseGlyphOrderDict()
 		glyphOrder = self.getGlyphOrder()
-		d = self._reverseGlyphOrderDict
-		if glyphName not in d:
+		d = self.getReverseGlyphMap()
+
+		glyphID = d.get(glyphName)
+
+		if glyphID is None:
+			# TODO This check is really expensive
 			if glyphName in glyphOrder:
-				self._buildReverseGlyphOrderDict()
-				return self.getGlyphID(glyphName)
+				return self._buildReverseGlyphOrderDict()[glyphName]
 			else:
 				# Handle glyphXXX only
 				if glyphName[:5] == "glyph":
@@ -556,12 +558,22 @@ class TTFont(object):
 					except (NameError, ValueError):
 						raise KeyError(glyphName)
 
-		glyphID = d[glyphName]
 		if glyphName != glyphOrder[glyphID]:
-			self._buildReverseGlyphOrderDict()
-			return self.getGlyphID(glyphName)
+			return self._buildReverseGlyphOrderDict()[glyphName]
+
 		return glyphID
 
+	def getGlyphIDMany(self, lst):
+		d = self.getReverseGlyphMap()
+
+		glyphIDs = [d.get(glyphName) for glyphName in lst]
+
+		if any(glyphID is None for glyphID in glyphIDs):
+			getGlyphID = self.getGlyphID
+			return [getGlyphID(glyphName) for glyphName in lst]
+
+		return glyphIDs
+
 	def getReverseGlyphMap(self, rebuild=False):
 		if rebuild or not hasattr(self, "_reverseGlyphOrderDict"):
 			self._buildReverseGlyphOrderDict()
@@ -570,8 +582,9 @@ class TTFont(object):
 	def _buildReverseGlyphOrderDict(self):
 		self._reverseGlyphOrderDict = d = {}
 		glyphOrder = self.getGlyphOrder()
-		for glyphID in range(len(glyphOrder)):
-			d[glyphOrder[glyphID]] = glyphID
+		for glyphID,glyphName in enumerate(self.getGlyphOrder()):
+			d[glyphName] = glyphID
+		return d
 
 	def _writeTable(self, tag, writer, done, tableCache=None):
 		"""Internal helper function for self.save(). Keeps track of